Body fat
Body fat percentage: ranges by sex and age
Where the Very low, Healthy, High and Very high ranges come from, and why they change with sex and age.
· 4 min read
Key points
- The ranges change with sex and age.
- They come from a study of 1,626 adults measured in the lab (Gallagher, 2000).
- Watch the trend: scales and watches vary from one day to the next.
Body fat percentage is the share of your weight that is fat. The rest is lean mass: muscles, bones, organs and water. It says more about body composition than weight alone, but there is no single official table of ranges. Many tables online do not say where they come from.
Where CatLena's ranges come from
CatLena uses the ranges from the study by Gallagher and colleagues, published in the American Journal of Clinical Nutrition in 2000 [1]. The researchers measured the body fat of 1,626 adults with a BMI of up to 35, at three universities (Cambridge, in the UK; Columbia, in the US; and Jikei, in Japan), using lab methods (DXA and the four-compartment model). They then calculated which body fat percentage matches the WHO BMI cut-offs: 18.5, 25 and 30.
The result is a set of ranges by sex and age. Women naturally carry more fat than men, and body fat rises with age for the same BMI:
| Age | Sex | Very low | Healthy | High | Very high |
|---|---|---|---|---|---|
| 20–39 | Women | < 21% | 21–33% | 33–39% | ≥ 39% |
| 40–59 | Women | < 23% | 23–34% | 34–40% | ≥ 40% |
| 60–79 | Women | < 24% | 24–36% | 36–42% | ≥ 42% |
| 20–39 | Men | < 8% | 8–20% | 20–25% | ≥ 25% |
| 40–59 | Men | < 11% | 11–22% | 22–28% | ≥ 28% |
| 60–79 | Men | < 13% | 13–25% | 25–30% | ≥ 30% |
Below essential
Part of body fat is essential: it sits in the nerves, bone marrow and cell membranes, and the body does not work well without it. In exercise physiology textbooks, it is about 3% in men and 12% in women [2]. Bodybuilders get close to it before competitions, for a short time and with a drop in hormones [3]. That is why CatLena adds one more range below Very low: below essential, under 5% for men and under 13% for women, at any age.
Very low body fat: it depends on weight
With a normal weight, body fat below the healthy range is typical of people who train a lot: a lean, athletic build. With a low weight, it may mean not eating enough. That is why CatLena looks at both together, in body composition.
About measuring it
Bioimpedance scales and watches estimate body fat and can vary quite a lot from one day to the next, for example with hydration. Compare readings taken the same way and look at the trend, not a single number.
How CatLena uses it
In the Body fat block, you log the reading from your scale or assessment, and CatLena splits your weight into lean mass and fat and shows the range for your sex and age. In the real example, 14.5% body fat at 67.4 kg: 57.6 kg of lean mass and 9.8 kg of fat, in the Healthy range.
The question mark (?) next to the measure opens the reference ranges for your sex and age in the app, with your range highlighted.
- In the Body fat card, the scale shows the five ranges for your sex and age, including below essential.
- The card also shows how much of your weight is lean mass and how much is fat.
- In Body composition, body fat is combined with BMI.
References
- Gallagher D, Heymsfield SB, Heo M, Jebb SA, Murgatroyd PR, Sakamoto Y. Healthy percentage body fat ranges: an approach for developing guidelines based on body mass index. American Journal of Clinical Nutrition, 2000;72(3):694–701. See the study
- McArdle WD, Katch FI, Katch VL. Exercise Physiology: Nutrition, Energy, and Human Performance. Wolters Kluwer. Body composition chapter: essential fat of Behnke's reference man and woman (about 3% and 12%).
- Rossow LM, Fukuda DH, Fahs CA, Loenneke JP, Stout JR. Natural bodybuilding competition preparation and recovery: a 12-month case study. International Journal of Sports Physiology and Performance, 2013;8(5):582–592. See the study
See this math done for you
In CatLena, you log workouts, meals and measurements (or just chat with CatLena) and the app does this math for you, every day, on your computer and phone.
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